Valve gate assembly

ABSTRACT

A valve gate assembly for regulating a flow of molten material into a mold. The valve gate assembly includes a movable valve that can move between a fully closed position and a fully open position. The valve gate assembly further includes an actuating system operatively cooperating with the valve to move the valve and infinitely position the valve between the fully closed position and the fully open position.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the priority date of copending U.S.Provisional Patent Application Ser. No. 60/519,312, filed Nov. 11, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to valve gates and, moreparticularly, to a valve gate assembly for regulating a flow of moltenmaterial into a cavity of a mold.

2. Description of the Related Art

Injection molding is a widely known manufacturing process used toproduce a variety of parts. Injection molding involves introducing amolten material, for example a molten plastic or resin, into a cavitywithin a mold until the cavity is filled. The molten material hardens orcures in the mold in the shape of inner surfaces of the cavity. Afterthe molten material hardens or cures, the hardened or cured material isremoved from the cavity.

For injection molding, a manifold is typically used for conveying moltenmaterial from a central injection portion or sprue to a number ofcavities or to multiple points within one large cavity of the mold. Anexample of such a manifold is disclosed in U.S. Pat. No. 4,964,795 toTooman. In that patent, a manifold has a passageway through which amolten material may pass. The terminal end of the passsageway, called agate, is in fluid communication with the cavity of the mold.

In addition, a valve gate is typically used with the manifold toregulate the flow of molten material into the cavity of the mold. Anexample of such a valve gate is disclosed in U.S. Pat. No. 4,173,448 toRees et al. In that patent, a valve gate is disposed adjacent the gateand includes a valve rod or pin partially disposed within the passagewaythat has a terminal end positioned such that it closes the gate andprevents the flow of molten material through the gate. However, the pincan move axially away from the gate and, as it moves farther away fromthe gate, the flow of the molten material through the gate increases.

It is known to provide an actuator to move the pin of the valve gate.Typically, the actuator is of a pneumatic or hydraulic type. Theactuator moves the pin of the valve gate from a fully closed position toa fully open position. In the fully open position, the pin is positionedaway from the gate, and molten material flows out the passageway throughthe gate into the cavity of the mold. When the cavity is full, the pinof the valve gate is moved to the fully closed position, therebyplugging the gate and stopping the flow of the molten material out ofthe passageway into the mold.

One disadvantage of the above-described valve gates is that thepneumatic actuator requires air valves because air is inconsistent inpressure. Another disadvantage of the valve gates is that the hydraulicactuator may leak oil, which is undesired. Yet another disadvantage ofthe valve gates is that the pin can only be positioned at the fully openposition or at the fully closed position, and cannot be positionedbetween these two positions. A further disadvantage of the valve gatesis that they are relatively slow and not very accurate in positioning ofthe pin.

Therefore, it is desirable to provide a new valve gate that can beinfinitely positioned between a fully opened and fully closed position,providing greater control over the flow of molten material into a mold.It is also desirable to provide a valve gate that has an actuator thateliminates the use of pneumatics or hydraulics. It is further desirableto provide a valve gate that has relatively fast actuation and accuratepositioning. Therefore, there is a need in the art to provide a valvegate that meets these desires.

SUMMARY OF THE INVENTION

Accordingly, the present invention is a valve gate assembly forregulating a flow of molten material into a mold. The valve gateassembly includes a movable valve that can move between a fully closedposition and a fully open position. The valve gate assembly furtherincludes an actuating system operatively cooperating with the valve tomove the valve and infinitely position the valve between the fullyclosed position and the fully open position.

One advantage of the present invention is that a valve gate assembly isprovided for regulating a flow of molten material into a mold with morecontrol over the molding process. Another advantage of the presentinvention is that the valve gate assembly can infinitely adjust theposition of the valve during the molding process, thereby adjusting theflow rate of the molten material into the mold. Yet another advantage ofthe present invention is that the valve gate assembly has fastadjustment of the valve and accurate adjustment of the valve to 0.001inches. Still another advantage of the present invention is that thevalve gate assembly eliminates the use of hydraulics, therebyeliminating oil leaks into the mold. A further advantage of the presentinvention is that the valve gate assembly eliminates the use ofpneumatics, thereby eliminating air valves. Yet a further advantage ofthe present invention is that the valve gate assembly is consistent andnot controlled by pressure.

Other features and advantages of the present invention will be readilyappreciated, as the same becomes better understood, after reading thesubsequent description taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary perspective view of a valve gate assembly,according to the present invention, illustrated in operationalrelationship with a manifold assembly and a mold.

FIG. 2 is an elevational view of one embodiment of an actuating system,according to the present invention, of the valve gate assembly of FIG.1.

FIG. 3 is an elevational view of another embodiment of an actuatingsystem, according to the present invention, of the valve gate assemblyof FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to the drawings, and in particular FIG. 1, one embodiment of avalve gate assembly 10, according to the present invention, is shown fora manifold assembly, generally indicated at 12, and a mold, generallyindicated at 14. The mold 14 has a first mold half 15 and a second moldhalf (not shown) defining a cavity 16 therein. The mold 14 also has atleast one, preferably a plurality of openings 18 extending through thefirst mold half 15 and fluidly communicating with the cavity 16. Itshould be appreciated that, when a molten material (not shown) isintroduced into the cavity 16 via the openings 18, the mold 14 containsthe molten material, and when the molten material hardens or cures, itholds a shape similar to that of the cavity 16. It should also beappreciated that the mold 14 is conventional and known in the art.

The manifold assembly 12 includes a manifold 20 having a manifold flowpassage 22. The manifold assembly 12 also includes as least one,preferably a plurality of nozzles 24 extending downwardly from themanifold 20 and having a nozzle flow passage 26 fluidly communicatingwith the manifold flow passage 22. The manifold assembly 12 furtherincludes a sprue 28 extending radially outward from the manifold 20 forfacilitating the introduction of molten material into the manifold 20.The flow passages 22 and 26 can be of any appropriate shape. The nozzleflow passage 26 narrows and terminates at a gate 30. As illustrated inFIG. 1, the mold 14 is positioned such that the gate 30 is positionedadjacent a respective opening 18 of the mold 14 to allow the nozzle flowpassage 26 fluid communication with the cavity 16. The valve gateassembly 10 cooperates with the gate 30 of the manifold assembly 12 tocontrol the flow of molten material from the manifold assembly 12 to themold 14. It should be appreciated that, although more than one valvegate assembly 10 may be used with the manifold assembly 12, only onevalve gate assembly 10 is used with one gate 30 of the manifold assembly12. It should also be appreciated that the molten material may be of aplastic, metal, wood fibers and plastic, etc. and is injected into thesprue 28 of the manifold assembly 20 from a molding machine (not shown).It should further be appreciated that the manifold assembly 12 isconventional and known in the art.

The valve gate assembly 10, according to the present invention, includesa moveable valve, generally indicated at 31, for regulating the flow ofmolten material into the cavity 16 of the mold 14. In one embodiment,the valve 31 is a pin or rod-like member 32 cooperating with the gate 30to regulate the flow of molten material into the cavity 16 of the mold14. In the embodiment illustrated, the pin 32 is axially aligned withthe gate 30 and is at least partially disposed within the nozzle flowpassage 26. The cross section of the pin 32 is preferably smaller thanthe cross section of the flow passage 26 such that the molten materialmay flow around the pin 32. The pin 32 includes an end 34 that opens andcloses the gate 30 in a manner to be described. It should also beappreciated that the pin 32 is conventional and known in the art.

The pin 32 can move axially within the flow passage 26 toward and awayfrom the gate 30 in a manner to be described. The pin 32 can bepositioned in a fully open position (i.e., at the top of its stroke),wherein its end 34 is positioned away from the gate 30. The pin 32 canalso be positioned in a fully closed position (i.e., at the bottom ofits stroke), wherein its end 34 is positioned within the gate 30.Preferably, the size of the end 34 is complementary to that of the gate30, allowing the end 34 to block and substantially seal the gate 30 whenthe pin 32 is in its fully closed position. As such, when the pin 32 isin the fully closed position, it seals the gate 30 and molten materialwill not flow therethrough. When the pin 32 is in the fully openposition, molten material will flow through the gate 30 into the mold14. It should be appreciated that the pin 32 can move between the fullyclosed and fully open positions and can be stopped at any positiontherebetween in a manner to be described. It should also be appreciatedthat the molten material flow through the gate 30 increases as the pin32 moves from the fully closed position to the fully opened position.

The valve gate assembly 10 also includes an actuating system 36,according to the present invention, operatively cooperating with the pin32 for moving the pin 32 between the fully closed and fully openpositions. In the embodiment illustrated in FIG. 2, the actuating system36 includes an actuator 38 operatively attached to the pin 32. Theactuator 38 axially or linearly moves the pin 32 away and toward thegate 30. The actuator 38 can infinitely position the pin 32 between thefully closed and fully open positions, meaning that the pin 32 can cometo rest at the fully closed position, the fully open position, andanywhere in between. In one embodiment, the entire range of movement(i.e., stroke) of the pin 32 between the fully closed and fully openpositions is approximately one inch. This infinite movement can occurincrementally. For example, in one embodiment, the actuator 38incrementally moves the pin 32 a predetermined amount such asapproximately 0.001 inch increments. By axially moving the pin 32, theactuating system 36 can seal and unseal the gate 30 as discussed ingreater detail below. It should be appreciated that the actuator 38 maybe a linear motor, brushless direct current (DC) motor, linearsynchronous motor, linear drive, linear servo, or linear tubular motor.It should also be appreciated that the actuator 38 may be of anelectromagnetic, earth magnetic, or electric type. It should further beappreciated that, as the increment becomes smaller, the positioning ormovement of the pin 32 becomes infinite.

In the embodiment shown in FIG. 2, the actuator 38 is of a linearinduction motor type. The actuator 38 includes a core 39 disposed aboutand connected to the pin 32 at an upper end thereof. The actuator 38also includes at least one, preferably a plurality of permanent magnets40 disposed axially and circumferentially about the core 39. Thepermanent magnets 40 are axially spaced by non-magnetic insulatingmembers 41 disposed axially and circumferentially about the core 39. Theactuator 38 includes a cylindrical housing 43 disposed about thepermanent magnets 40 and the insulating members 41. It should beappreciated that the pin 32, core 39, permanent magnets 40, insulatingmembers 41, and housing 43 move as a single unit.

The actuator 38 includes at least one, preferably a plurality ofelectromagnets 42 spaced axially and disposed circumferentially aboutthe permanent magnets 40. The actuator 38 also includes an electricalconnector 44 electrically connected to the electromagnets 42 and asource of power such as a controller 46 to be described. The actuator 38includes a cylindrical housing 45 a disposed about the electromagnets 42and an upper end plate 45 b closing one end of the housing 45 a and alower end plate 45 c closing the other end of the housing 45 a. Theelectrical connector 44 is connected to the upper end plate 45 b bysuitable means such as a fastener 44 a. It should also be appreciatedthat, when the electromagnets 42 are in the correct position relative tothe permanent magnets 40, the electromagnets 42 are energized by thecontroller 46 and repel the permanent magnets 40 to move the core 39 andpin 32 linearly.

The actuator 38 includes a plate 47 at a lower end for attachment to themanifold 20. The plate 47 has a locator 48 extending axially therefromfor locating the plate 47 relative to the manifold 20. The locator 48has an aperture 49 extending axially therethrough through which the pin32 extends. The locator 48 is located in a recess 50 of the manifold 20and the plate 47 is attached to the manifold 20 by suitable means suchas fasteners 51 a. The plate 47 is attached to the lower end plate 45 cby suitable means such as fasteners 51 b. The actuator 38 includes amoveable plate 52 at an upper end thereof. The plate 52 is attached tothe upper end of the pin 32. It should be appreciated that theelectromagnets 42 and plate 47 are fixed relative to the manifold 20.

The actuating system 36 also includes an encoder 54. The encoder 54 maybe of any appropriate type, including linear and rotary encoders. Theencoder 54 may employ any appropriate position sensing mechanism. In oneembodiment, the encoder 54 includes a sensing device 56 such as aphotodetector. The encoder 54 is attached to the movable plate 52 suchthat the encoder 54 travels with the pin 32. Also, the sensing mechanism56 is fixedly attached to the actuator 38 and disposed parallel to thetravel of the pin 32. As such, when the pin 32 moves, the encoder 54moves relative to the sensing mechanism 56 and detects the change inposition as the encoder 54 travels linearly. The sensing device 56translates the change in position (i.e., the position of the pin 32) toan electronic encoder signal. It should be appreciated that the sensingdevice 56 is electrically connected to the controller 46 to bedescribed.

The actuating system 40 further includes a controller 46 electricallyconnected to the sensing device 56 and the actuator 38. The controller46 receives the encoder signals and translates these encoder signalsinto a control signal. The controller 46 sends these control signals tothe actuator 38 to energize and deenergize the electromagnets 42 of theactuator 38, thereby causing the actuator 38 to move the pin 32 towardor away from the gate 30. It should be appreciated that the controller46 may be any suitable type of computer, for example, a personalcomputer (PC) or a programmable logic controller (PLC).

The valve gate assembly 10 includes an input device 58, such as akeyboard, electrically connected to the controller 46. With the inputdevice 58, a user can manually input information to the controller 46,such as the desired position of the pin 32.

In operation, the molding process can begin with the pin 32 in the fullyclosed position such that the molten material in the manifold assembly12 is prevented from flowing into the cavity 16 of the mold 14. When itis determined to allow molten material into the cavity 16 of the mold14, the controller 46 sends control signals to the actuator 38 toenergize and de-energize the electromagnets 42 to repel the permanentmagnets 40 and move them linearly, which actuates the pin 32 and movesthe end 34 of the pin 32 linearly away from the gate 30. The sensingmechanism 56 detects the change in position of the pin 32 via theencoder 54, and feeds back encoder signals to the controller 46. Whenthe pin 32 reaches the desired position, the controller 46 receives thecorresponding encoder signals and the controller 46 stops sendingcontrol signals to the actuator 38, thereby stopping the actuator 38from actuating. When the pin 32 is in the desired open position, themolten material flows through the passageway 26 and gate 30 and into thecavity 16 of the mold 14. It should be appreciated that the actuator 38can infinitely position the pin 32 anywhere between the fully closed andfully open positions and allows for quick and accurate adjustment of theflow of molten material into the cavity 16 of the mold 14.

Referring to FIG. 3, another embodiment, according to the presentinvention, of the actuating system 36 is shown. Like parts of theactuating system 36 have like reference numerals increased by onehundred (100). In this embodiment, the actuating system 136 includes theactuator 138 operatively attached to the pin 132. The actuator 138 is ofa linear motor type. The actuator 138 includes a core 139 disposed aboutand connected to the pin 132 at an upper end thereof. The actuator 138includes a rotatable nut 160 and a hollow ball screw 162 connected tothe core 139 and threadably engaged with the nut 160 for cooperatingwith the nut 160. The actuator 138 also includes at least one,preferably a plurality of electromagnets 142 spaced axially and disposedcircumferentially about the core 139. The actuator 138 also includes anelectrical connector (not shown) electrically connected to theelectromagnets 142 and a source of power such as a controller 146. Theactuator 138 includes a cylindrical housing 145 a disposed about theelectromagnets 142 and an upper end plate 145 b closing the upper end ofthe housing 145 a. The upper end plate 145 b is connected to the housing145 a by suitable means such as fasteners 160.

The actuator 138 includes a plate 147 at a lower end for attachment tothe manifold 20. The plate 147 has a locator 148 extending axiallytherefrom for locating the plate 147 relative to the manifold 20. Thelocator 148 has an aperture 149 extending axially therethrough throughwhich the pin 132 extends. The plate 147 is attached to the housing 145a by suitable means such as fasteners 151 b.

The actuating system 136 also includes an encoder 154. The encoder 154is a rotary encoder. The encoder 154 includes a sensing device 156 suchas a photodetector. The encoder 154 is attached to the rotatable nut160. Also, the sensing mechanism 156 is fixedly attached to the actuator138. As such, when the nut 160 rotates and the pin 132 moves, theencoder 154 moves relative to the sensing mechanism 156 and detects thechange in position as the encoder 154 rotates. The sensing device 156translates the change in position (i.e., the position of the pin 132) toan electronic encoder signal. It should be appreciated that the sensingdevice 156 is electrically connected to the controller 146.

In operation, the molding process can begin with the pin 132 in a fullyclosed position such that molten material in the manifold assembly 12 isprevented from flowing into the cavity 16 of the mold 14. When it isdetermined to allow molten material into the cavity 16 of the mold 14,the controller 146 sends control signals to the actuator 138 to energizeand de-energize the electromagnets 142 to rotate the nut 160. Rotationof the nut 160 moves the ball screw 162 linearly, which actuates the pin132 and moves the end 134 of the pin 132 linearly away from the gate 30.The sensing mechanism 156 detects the change in position of the pin 132via the encoder 154, and feeds back encoder signals to the controller146. When the pin 132 reaches the desired position, the controller 146receives the corresponding encoder signals and the controller 146 stopssending control signals to the actuator 138, thereby stopping theactuator 138 from actuating. When the pin 132 is in the desired openposition, the molten material flows through the passageway 26 and gate30 and into the cavity 16 of the mold 14.

Accordingly, the valve gate assembly 10 provides the user with morecontrol during the molding process by allowing the pin 32, 132 positionto be infinitely adjusted. For example, a molding process may be workingeffectively; however, environmental changes or wear in the mold mightrender that process less effective. The valve gate assembly 10 of thepresent invention allows the user to make changes to the process (i.e.,changes in pin position or actuation timing), thereby maintaining theproduction of quality parts.

The present invention has been described in an illustrative manner. Itis to be understood that the terminology, which has been used, isintended to be in the nature of words of description rather than oflimitation.

Many modifications and variations of the present invention are possiblein light of the above teachings. Therefore, within the scope of theappended claims, the present invention may be practiced other than asspecifically described.

1. A valve gate assembly for regulating a flow of molten material into amold comprising: a movable valve that can move between a fully closedposition and a fully open position; and an actuating system operativelycooperating with said valve to move said valve and infinitely positionsaid valve between the fully closed position and the fully openposition.
 2. A valve gate assembly as set forth in claim 1 wherein saidactuating system includes an actuator operatively attached to saidvalve.
 3. A valve gate assembly as set forth in claim 2 wherein saidactuating system includes an encoder operatively attached to said valve.4. A valve gate assembly as set forth in claim 3 wherein said actuatingsystem includes a sensing device spaced from said encoder for detectinga position of said encoder and translating the position of said encoderinto an encoder signal.
 5. A valve gate assembly as set forth in claim 4wherein said actuating system includes a controller electricallyconnected to said actuator and said sensing device for receiving theencoder signal, translating the encoder signal into a control signal,and sending the control signal to said actuator, the control signalcausing said actuator to move said valve and position said valve betweenthe fully closed position and the fully open position.
 6. A valve gateassembly as set forth in claim 1 wherein said valve comprises a pinextending axially and having one end attached to said actuator andanother end capable of moving toward and away from a gate of the mold.7. A valve gate assembly as set forth in claim 6 wherein said pin has astroke of approximately one inch.
 8. A valve gate assembly as set forthin claim 6 wherein said pin can be incrementally positioned by saidactuator.
 9. A valve gate assembly as set forth in claim 5 wherein saidactuating system includes an input device connected to said controllerwith which a user can input a stopped position of said valve varyingbetween the fully closed position and the fully open position.
 10. Avalve gate assembly as set forth in claim 3 wherein said encodercomprises either one of a linear encoder and a rotary encoder.
 11. Avalve gate assembly as set forth in claim 3 wherein said actuatorincludes a core connected to said valve, at least one permanent magnetdisposed about said core, and at least one electromagnet disposed aboutsaid permanent magnet for moving said valve.
 12. A valve gate assemblyas set forth in claim 11 including a movable plate operatively attachedto said valve, said encoder being supported by said plate.
 13. A valvegate assembly as set forth in claim 3 wherein said actuator includes acore attached to said valve, a ball screw disposed about said core, arotatable nut threadably engaged with said screw, and at least oneelectromagnet disposed about said nut and being operable to rotate saidnut for moving said valve.
 14. A valve gate assembly as set forth inclaim 13 including a rotatable plate operatively attached to said nut,said encoder being supported by said plate.
 15. A valve gate assembly asset forth in claim 2 including a plate attached to said actuator, saidplate having a locator extending axially and being adapted to locatesaid actuator relative to the mold.
 16. A valve gate assembly as setforth in claim 2 wherein said actuator is one of a group comprising alinear motor, a brushless direct current motor, a linear synchronousmotor, a linear drive motor, a linear induction motor, a linear servomotor, a linear tubular motor, an electro-magnetic actuator, an earthmagnetic actuator, and an electric type actuator.
 17. A valve gateassembly for regulating a flow of molten material into a moldcomprising: a movable pin that can move between a fully closed positionand a fully open position; an actuator operatively attached to said pinfor moving said pin and infinitely positioning said pin between thefully closed position and the fully open position; an encoderoperatively attached to said pin; a sensing device spaced from saidencoder for detecting a position of said encoder and translating theposition of said encoder into an encoder signal; and a controllerelectrically connected to said actuator and said sensing device forreceiving the encoder signal, translating the encoder signal into acontrol signal, and sending the control signal to said actuator, thecontrol signal causing said actuator to move said pin and position saidpin between the fully closed position and the fully open position.
 18. Avalve gate assembly as set forth in claim 17 wherein said pin has astroke of approximately one inch.
 19. A valve gate assembly as set forthin claim 17 wherein said pin can be incrementally positioned by saidactuator.
 20. A valve gate assembly as set forth in claim 17 includingan input device connected to said controller with which a user can inputa stopped position of said pin varying between the fully closed positionand the fully open position.
 21. A valve gate assembly as set forth inclaim 17 wherein said encoder comprises either one of a linear encoderand a rotary encoder.
 22. A valve gate assembly as set forth in claim 17wherein said actuator includes a core connected to said pin, at leastone permanent magnet disposed about said core, and at least oneelectromagnet disposed about said permanent magnet for moving said pin.23. A valve gate assembly as set forth in claim 17 including a movableplate operatively attached to said pin, said encoder being supported bysaid plate.
 24. A valve gate assembly as set forth in claim 17 whereinsaid actuator includes a core attached to said pin, a ball screwdisposed about said core, a rotatable nut threadably engaged with saidscrew, and at least one electromagnet disposed about said nut and beingoperable to rotate said nut for moving said pin.
 25. A valve gateassembly as set forth in claim 24 including a rotatable plateoperatively attached to said nut, said encoder being supported by saidplate.
 26. A valve gate assembly as set forth in claim 17 including aplate attached to said actuator, said plate having a locator extendingaxially and being adapted to locate said actuator relative to the mold.27. A valve gate assembly as set forth in claim 17 wherein said actuatoris one of a group comprising a linear motor, a brushless direct currentmotor, a linear synchronous motor, a linear drive motor, a linearinduction motor, a linear servo motor, a linear tubular motor, anelectro-magnetic actuator, an earth magnetic actuator, and an electrictype actuator.
 28. A valve gate assembly for regulating a flow of moltenmaterial into a mold comprising: a movable pin that can move between afully closed position and a fully open position; an actuator operativelyattached to said pin for moving said pin and infinitely positioning saidpin between the fully closed position and the fully open position; saidactuator comprising a core connected to said pin, at least one permanentmagnet disposed about said core, and at least one electromagnet disposedabout said permanent magnet for moving said pin; an encoder operativelyattached to said actuator; a sensing device spaced from said encoder fordetecting a position of said encoder and translating the position ofsaid encoder into an encoder signal; and a controller electricallyconnected to said actuator and said sensing device for receiving theencoder signal, translating the encoder signal into a control signal,and sending the control signal to said actuator, the control signalcausing said actuator to move said pin and infinitely position said pinbetween the fully closed position and the fully open position.
 29. Avalve gate assembly for regulating a flow of molten material into a moldcomprising: a movable pin that can move between a fully closed positionand a fully open position; an actuator operatively attached to said pinfor moving said pin and infinitely positioning said pin between thefully closed position and the fully open position; said actuatorcomprising a core attached to said pin, a ball screw disposed about saidcore, a rotatable nut threadably engaged with said screw, and at leastone electromagnet disposed about said nut and being operable to rotatesaid nut for moving said pin; an encoder operatively attached to saidactuator; a sensing device spaced from said encoder for detecting aposition of said encoder and translating the position of said encoderinto an encoder signal; and a controller electrically connected to saidactuator and said sensing device for receiving the encoder signal,translating the encoder signal into a control signal, and sending thecontrol signal to said actuator, the control signal causing saidactuator to move said pin and infinitely position said pin between thefully closed position and the fully open position.